import type { H3Event } from "h3";
import { createError, getRequestHeader } from "h3";
export async function readBounded(
  event: H3Event,
  max: number,
): Promise<Buffer> {
  const declared = getRequestHeader(event, "content-length");
  if (declared && (!/^\d+$/u.test(declared) || Number(declared) > max))
    throw createError({
      statusCode: 413,
      statusMessage: "Request body exceeds the limit.",
    });
  const chunks: Buffer[] = [];
  let total = 0;
  for await (const value of event.node.req) {
    const chunk = Buffer.isBuffer(value) ? value : Buffer.from(value);
    total += chunk.byteLength;
    if (total > max)
      throw createError({
        statusCode: 413,
        statusMessage: "Request body exceeds the limit.",
      });
    chunks.push(chunk);
  }
  return Buffer.concat(chunks, total);
}
export async function readJson<T>(event: H3Event, max: number): Promise<T> {
  const body = await readBounded(event, max);
  try {
    return JSON.parse(body.toString("utf8")) as T;
  } catch {
    throw createError({ statusCode: 400, statusMessage: "Malformed JSON." });
  }
}
export function requireContentType(event: H3Event, expected: string) {
  const type = (
    (getRequestHeader(event, "content-type") || "").split(";", 1)[0] || ""
  )
    .trim()
    .toLowerCase();
  if (type !== expected)
    throw createError({
      statusCode: 415,
      statusMessage: `Content-Type must be ${expected}.`,
    });
}
export function bearerToken(event: H3Event): string | undefined {
  const value = getRequestHeader(event, "authorization") || "";
  return /^Bearer ([A-Za-z0-9_-]{20,})$/u.exec(value)?.[1];
}
export function publicHeaders(event: H3Event) {
  event.node.res.setHeader("cache-control", "no-store");
  event.node.res.setHeader("referrer-policy", "no-referrer");
  event.node.res.setHeader("x-content-type-options", "nosniff");
}